THERMODYNAMIC MODEL OF A LIQUID

In this model the thermal vibrations of atoms with respect to their po sitions of equilibrium are described in a modified Debye approximation which at high temperatures and low densities changes to the descripti on of an ideal gas. The elastic (cold) component of the free energy di ffers from that of a solid by lower values of the density and heat vap orization at zero temperatures. A configurational component, which is peculiar to a liquid and which characterizes the degree of disorder in the liquid, is introduced. The thermodynamics of neon is studied, iso therms of the free energy and pressure are constructed, and solid-liqu id, solid-gas, and liquid-gas phase transitions are described. (C) 199 5 American Institute of Physics.